Elevator Door Drive Regulating Speed via Electromagnetic Induction
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Solution Overview
Problem
Elevator door closing devices face issues with excess speed and prolonged closing times during power failures, leading to safety risks and inefficiencies due to the lack of effective energy management and control mechanisms.
Innovation Solution
A device comprising a door leaf, an energy store, a door drive, and a door control system that induces electrical energy during the closing movement to regulate the speed of the door leaf, utilizing the potential energy from the energy store to ensure a controlled and rapid closure, preventing excessive speeds and maintaining operation of the door control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an energy store is used to close the door leaf during power failure, then the door can be closed without electrical power, but the door leaf accelerates to excessive speeds causing safety risks
Solution Approach 1:
The patent converts the harmful excess kinetic energy of the accelerating door leaf into useful electrical energy through electromagnetic induction in the motor. This regenerated energy is then used to power the control device, transforming the safety hazard into a beneficial energy source that enables controlled closing while maintaining operational reliability.
Solution Approach 2:
The control device uses feedback from speed sensors to continuously monitor the door leaf velocity and dynamically adjust the braking torque applied by the motor. This closed-loop control ensures the door closes safely by reducing speed when necessary while still utilizing the energy store's potential energy for closing operation during power failures.
2Object-affected harmful factors
If braking forces are applied to the door leaf during power failure, then excessive speed is prevented, but closing time increases significantly
Solution Approach 1:
The patent employs dynamic braking control where the motor transitions from motor mode to generator mode during door closing. The braking torque is not applied continuously but dynamically adjusted based on real-time speed feedback, allowing the door to accelerate initially for fast closing while applying braking only when speed exceeds safe thresholds, thus optimizing both speed control and closing time.
Solution Approach 2:
The system changes the operational parameters of the motor from motor mode to generator mode, and dynamically adjusts the braking torque magnitude based on door leaf speed. This parameter variation allows the system to achieve both fast closing and safe speed control by adapting the braking force to the instantaneous operational conditions.
3Object-affected harmful factors
If costly resistance-based braking systems are used to convert kinetic energy to heat, then door speed is controlled, but system cost and energy efficiency decrease
Solution Approach 1:
Instead of dissipating kinetic energy as heat through resistances, the patent uses electromagnetic induction to convert the door leaf's kinetic energy into electrical energy. This regenerated energy is fed back to power the control device, transforming what would be wasted energy into a useful resource, thereby improving energy efficiency while maintaining speed control.
Solution Approach 2:
The patent replaces the mechanical/thermal braking system (resistances converting kinetic energy to heat) with an electromagnetic energy recovery system. The motor acts as a generator during braking, converting mechanical kinetic energy directly into electrical energy, which is then used to power the control electronics, eliminating energy dissipation and reducing system cost.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables a controlled and efficient closure of the elevator door during power failures, reducing the risk of excessive speeds and ensuring safe operation by converting excess energy into electrical energy to power the door control, thus maintaining a gentle and fast closing movement.
Implementation Method 1
electrical energy can be induced in a door drive in the case of closing movement of the door leaf
Data Source
AI summary
A device for preventing excess speed, which is caused by an energy store, of a door leaf, includes a door leaf displaceable between an open position and a closed position, an energy store coupled with the door leaf, which energy store provides energy for the closing movement of the door leaf in the event of failure of the electrical energy supply, a door drive coupled with the door leaf, wherein electrical energy can be induced in the door drive when closing movement of the door leaf takes place, and a door control, which activates the door drive and which is suitable for regulation of the speed of movement of the door leaf, wherein the door control is operable by the induced electrical energy when the electrical energy supply fails, and a method of operating an elevator door.